Amalgam loader

ABSTRACT

Apparatus for loading a tube with amalgam or other pastey substance in which a plurality, preferably three, rollers are equiangularly spaced close together to define among them a central passageway, the apparatus having means for locating the tube to be filled below the passageway created by the rollers. The rollers are operable to roll a charge of amalgam into a roll having a diameter slightly less than that of the tube to be filled, whereupon the amalgam passes through the passageway and into the tube.

United States Patent [191 Baker AMALGAM LOADER [75] Inventor: Ronald LeeBaker, Florence, Ky.

[73] Assignees: Charles J Thiel; Louis J. Michaels, D ayton, Ky. 1

22 Filed: May 19,1972

2| Appl. No.: 255,179

[52] US. Cl 141/18, 259/DlG. 20, 259/6 [51] Int. Cl A6lc 5/06 [58] Fieldof Search...'. 259/5, 6, DlG. 20,

[56] References Cited UNITED STATES PATENTS 2,175,321 10/1939 Saffir259/DlG. 20 3,222,037 12/1965 Thiel et al.....

[ Jan. 15, 1974 3,368,592 2/1968 Thiel et al 259/72 X PrimaryExaminer-Willian1 I. Price Attorney.lames S. l-light et al.

57 ABSTRACT Apparatus for loading a tube with amalgam or other pasteysubstance in which a plurality, preferably three,

rollers are equiangularly spaced close together to define among them acentral passageway, the apparatus having means for locating the tube tobe filled below the passageway created by the rollers. The rollers areoperable to roll a charge of amalgam into a roll having a diameterslightly less than that of the tube to be filled, whereupon the amalgampasses through the passageway and into the tube.

20 Claims, 6 Drawing Figures Ell PAIENIEU JAN 1 51974 mu 1 BF 2 AMALGAMLOADER This invention relates to a method and apparatus for loadingamalgam into a tube which forms a part of the dental dispenser utilizedby a dentist for filling teeth.

In U.S. Pat. No. 3,222,037, Thiel et al. have described apparatus forloading amalgam into a tube. The objective of the invention there aswellas here is to minimize the handling of amalgam as much as possible andto reduce the contaminates to which the amalgam is exposed in thepresent practices of mixing and loading dispensers. Earlier inventorshad noted the desirability of dispensing amalgam from a tube, but nonehad suggested a feasible way of getting amalgam into the tube. By itsvery nature, amalgam tends to be difficult to work with for it so easilycompacts, thereby frustrating efforts to force amalgam into a tubethrough any conventional approach.

The invention of the Thiel et al patent provided a solution to theproblem of loading amalgam into the tube, the invention utilizing acapsule with a tube mounted on one end of the capsule and a pestle fordriving the amalgam out of the capsule into the tube. The capsule whenmounted on an agitating device caused the amalgam to flow from thecapsule into the tube. The invention of that patent has provedsatisfactory in every respect insofar as the operation is concerned.However, present practices in dentists office's give rise to a need fora different and perhaps more universal loading apparatus. For example,the throw-away capsules containin g the amalgam constituents are verypopular, particularly with the dental assistants who prefer them toreusable capsules which must be cleaned from time to time. Additionally,there are a wide amalgamators of amalgamotors used in dentists offices,and it might not seem economically feasible to add a combinationamalgamator-loader to an office already having a satisfactoryamalgamator. v t

It has therefore been an objective of the present invention to provide aloader for premixed amalgam, that is, amalgam which is mixed in any typeof amalgamator including those amalgamators which employ disposablecapsules.

To this end the'invention contemplates the provision of a group ofrollers inclined outwardly to provide a funnel, the lower extremities ofthe rollers defining a passageway through which a roll or stream ofamalgam passes. A gob of amalgam disposed centrally of the rollers will,upon rotation of the rollers, be caused to take the shape of a rollhaving a very small diameter, that roll of amalgam being capable ofsliding into a tube, thereby to load the tube.

As shown in Thiel et al. U.S. Pat. No. 3,221,409, one form of thedispenser tube is curvilinear. Loading such a curvilinear tube mountedimmediately below the lower extremities of the rollers has proveddifficult for the amalgam tends to become jammed before complete entryinto the tube. It has therefore been another objective of the inventionto provide for the filling of the curvilinear tube in the apparatus ofthe present invention by interposing a straight tube between the lowerextremities of the rollers and the curved tube to be loaded. Thestraight tube forms asecondary passage permitting the roll of amalgam tobe fully formed before it begins its movement into the curvilinear tube.

Another objective of the invention has been to improve the shape of thecurvilinear tube to facilitate its manufacture, loading and to tend toassure freedom from clogging in use- In this regard, the tube of thepresent invention is formed with its center axis forming an arc of acircle preferably on approximately a 1 inch radius. Further, the tubehas a slight taper, being approximately 0.004 inch wider at itsdischarge end than at the opposite end. g

In early models of the invention, it was found that on occasion theamalgam would simply rest among the rollers as they were rotatingwithout becoming formed into an elongated roll suitable for introductioninto the tube. To provide substantially complete reliability insofar asthe performance of the apparatus is concerned, two features have beenadded. First, at least one of the rolls, and preferably all of them,have had a'plurality of dimples formed in their surface to provide asomewhat roughened surface whereby the rollers effectively work on theamalgam as they rotate. It has also been found that the reliability ofthe apparatus is improved if the amalgam is in the form of a ball whenit is introduced between the rollers. Therefore, as a further improvement into the invention, means areprovided for rolling mixed amalgaminto a ball before it is disposed between the rollers.

As a further feature of the invention, provision is made to receive adispenser of the type to be filled by the invention, the tube of thedispenser being located immediately below the straight tube dependingfrom the rollers. The receiver for the dispenser is provided with aswitch which causes the automatic operation of the motor which drivesthe rollers, or alternatively to provide for the operation of the switchupon slight depressing of the dispenser.

Still another feature of the .invention has been to provide guidefingers located between adjacent rollers, the guide fingers providinggreater assurance of the confining of the amalgam to a location centralof the rollers.

The several objectives and features of the invention will become morereadily apparent from the following detailed description taken inconjunction with the drawings in which:

FIG. 1 is a sideelevational view partly in section of the apparatus;

FIG. 2 is a top plan view of the roller system taken along lines 2-2 ofFIG. 1;

FIG. 3 is a cross sectional view through the straight tube and dispensertube illustrating the physical and dimensional relationship;

FIG. 4 shows an alternative embodiment for loading a straight tube withan automatic switch;

FIG. 5 is a plan view of an alternative embodiment illustrating the useof guide fingers associated with the rollers; and

FIG. 6 is a diagrammatic view illustrating the use of a device forforming a ball of the amalgam before it is introduced between therollers.

In FIG. 1 the loading apparatus is indicated generally at 10 and shownin position for loading a dispenser indicated at 11, the dispenser beinggenerally of the form shown in Thiel et al. U.S. Pat. No.- 3,221,409.

The loading apparatus includes a base 12, a column 13, the column 13supporting a housing 14 which contains the rollers and associatedapparatus. The housing 14 has a bottom wall 15 projecting out of thecolumn 13.

Three rollers 18, approximately one-half inch in diameter, are rotatablymounted on a base 19 which is in turn mounted on the bottom wall of thehousing. The rollers are rotatably mounted by means of three pins 21fixed in the base 19. The pins are angled outwardly by an angle ofapproximately 2 to the vertical. The axes of the rollers are alsoinclined toward the side through an angle of approximately 4. Morespecifically, the outward swing of the axis through 2 defines a plane.The sidewise swing through 4 is through a plane perpendicular to thatfirst plane. The outward angulation creates the funnel relationship ofthe rollers. The sidewise angulation, coupled with the speed ofrotation, causes the surface of the rollers to impart a downwardcomponent of force on the amalgam. For example, as each roller is viewedfrom the apex of the triangle which the three form, the roller leans tothe left. When viewed from above, the rollers rotate counterclockwise.The rollers are simply slidably mounted on the pins, the axes of therollers having the same angulation as the axes of the pins.

In the preferred embodiment, each roller is driven approximately 500rpm, but this speed of rotation is subject to considerable variationwithout affecting anything except the speed with which the amalgam isformed into a roll and loaded. Asillustrated in FIGS. 1 and 2, therollers are driven by an endless belt 24 which passes around the groupof rollers into contact with each of them and around a pulley 25. Thepulley 25 is fixed to a shaft 26 carrying a larger pulley 27 aroundwhich a second belt 28 passes, the second belt passing around a driveshaft 29 of a motor 30. As shown in FIG. 2, the rollers have lower edgesor extremities 32 which together define a passageway 33 through which aroll of amalgam, formed by the rollers, passes. The innermost points,indicated at 34, of the lower extremities of the rollers define animaginary circle indicated by the dotted line 35 having a diameter A.The diameter A is the approximate diameter of the roll of amalgam as itpasses through the passageway 33. That diameter preferably is a fewthousandths of an inch smaller than the tube which it is to fill.

The housing has an outer wall 38 having an opening 39 in its uppersurface, the opening 39 overlying the rollers 18. The wall has a moldedtaper indicated at 40 to guide a ball of amalgam to the opening 39 sothat it will drop into the space formed among the three rollers.

As illustrated in FIG. 3, the base 19 and bottom wall 15 of the housing14 have a hole 42 therethrough into which a straight tube 43 is mounted,the hole 42 and straight tube 43 being located immediately below therollers 18 and coaxial with the imaginary circle 35 defined by the lowerextremities of the rollers. The straight tube has a center passageway 45of a diameter B slightly greater than the diameter of the imaginarycircle 35 so that amalgam formed of the diameter A will pass easilythrough the straight tube passageway 45. The lower end of the tube 45has a flared opening 46 to receive the discharge end 47 of a dispensertube 48 which is to be loaded. The tube 48 has a tapered passageway 49whose larger diameter C at the discharge end 47 is slightly greater thanthe diameter B of the straight tube passageway 45. The dispenserpassageway 49 tapers down to a smaller diameter D at its inner end 50.

The dispenser tube 48 is curved, having a curvilinear of a 1 inch radiuscircle.

Satisfactory results have been achieved with the apparatus of theinvention when the dimensional relationships are as follows, theserelationships being set forth herein for example and not by way oflimitation:

Diameter A 0.095

Diameter B 0.102

Diameter C 0.104

Diameter D 0.100

A dispenser receiver 55 is mounted below the housing 14 and has a seat56 to receive the dispenser 11. The bottom of the seat is formed by aswitch operator 57 pivoted at 58 to the receiver. The operator 57 has awall 59 engageable with a microswitch 60 mountd in the receiver. It canbe seen that mounting the dispenser in the dispenser receiver, by firstpositioning the curved tube 48 in the flared socket 46 of the straighttube 43, causes a tube mounting collet 62 in the end of the dispenser torest upon the operator 57. Depending upon the spring loading of eitherthe microswitch or the operator 57, the positioning of the dispenser asshown will cause the switch to operate, or alternatively, a slightdepression of the dispenser 11 will overcome the spring resistance ofthe microswitch or operator and cause the switch to operate. Themicroswitch 60 is connected at the circuit with the motor 30 so thatclosing of the microswitch causes the motor to run and the rollers torotate.

As a feature of the invention, provision is made for forming amalgaminto a generally spherical ball. As illustrated in FIG. 6, aball-forming accessory 65 is mounted on the top of the housing having adischarge port 66 overlying the opening 39 at the top of the housing.The apparatus includes a block 68 having a circular groove 69 into whichamalgam to be balled is dropped. A flexible wiper 70 is secured to anarm 71 rotatably mounted on an integral shaft 72 at the block 68. As theshaft 72 rotates, the wiper 70 revolves about the groove 69, pushing theamalgam ahead of it until a ball is formed. The shaft 72 is driven bythe motor 30, the shaft 72 being connected by a coupling 73 to the shaft26.

The block 68 has a valve 74 constituted by a plug 75 mounted in atransverse hole 76 forming a communication between the groove 69 and theopening 66. The plug 75 has a transverse hole 77 through it and a groove78 in one surface of it, the groove 78 normally forming a continuationof the groove 69 when the plug is rotated to bring the groove to anupwardly facing position. It is in that attitude, as illustrated in FIG.3, that the amalgam is formed into a ball. After the amalgam has beenformed into a ball, the plug 75 is rotated through an angle of 90 tobring the hole 77 into a vertical attitude so that the ball dropsthrough the hole and into the rollers.

As an alternative to the automatic ball former, the amalgam can beformed into a ball in a squeeze cloth frequently used in the preparationof amalgam.

A modification of the invention is illustrated in FIG. 4. There, when astraight tube is to be loaded, the straight tube 43 and dispenserreceiver 55 can be eliminated. A straight tube is used, for example,with a dispenser packer of the type illustrated in Thiel et al.application, Ser. No. 198,185. In the modification of FIG. 4, thestraight tube 80, with one end stoppered as at 81, is held immediatelybelow the opening 42 through the housing bottom wall 15 and base 19. Aflange on the collet or mounting end 82 of the straight tube 80 engagesa microswitch actuating lever 83, which actuates I H6. 5. There, a groupof three guide fingers 86, de-

pending from the top of the housing 14, projects between adjacent rolls16 to provide additional assurance of the confining of the amalgam intocentral position between the rollers during the roll-forming operation.

While in the preferred form of the invention three generally verticaloriented rollers have been illustrated, it should be understood that theinvention is not restricted to that configuration. For example, threeconically shaped rollers could be employed, the cones having their baseslocated adjacent the base 19. The conical shaped rollers would obviatethe need for outward canting of the cylindrical rollers.

Further, more than the three illustrated rollers could be employed aslong as their grouping is such as to form a small enough passagewayamong them to reduce the glob of amalgam to a roll of a diametersuitable for insertion into the dispenser tube.

Still further, it would be possible to form the amalgam into a rollusing only two rollers lying in a generally horizontal attitude, butthis configuration would not be as convenient to useas the threevertically oriented rollers.

In the operation of the invention, including the modification of FIG. 6,the amalgam is first mixed in any one of the standard amalgamators. Themixed amalgam is disposed in the groove69 of the ball former 65. Adispenser, previously positioned in the receiver 55, is depressed toactuate the microswitch 60 as described above. The energization of themotor 30 causes the rollers to rotate and causes the shaft 72 to rotateand the wiper 70 carried by it to revolve about the groove. As the wiperrevolves about the groove, the amalgam is rolled into a ball. When theball is formed, the plug 75 is rotated to bring the transverse hole 77into communication with the groove 69, whereupon the ball drops in amongthe rollers 18. As the rollers continue to rotate for just a fewadditional seconds, approximately four in the preferred embodiment, theball is formed into an elongated roll of amalgam which passes throughthe opening 42 in the base 19 and bottom wall into the straight tube 43.Following passage through the straight tube 43, the roll slides into thedispenser tube 48, whereupon it is ready for deposit into a patientstooth. It can be observed that throughout the whole operation there hasbeen no requirement for the amalgam to touch the hands of a dentalassistant and, hence, the possibility of contaminates, for example,moisture, from the dental assistants hands is substantially eliminated.

1 claim: 1

ll. Apparatus for loading amalgam or the like into a tube comprising,

a support,

at least three rollers mounted generally vertically on said support onequiangularly spaced axes, the lower extremities of said rollersdefining among them a discharge passageway, means for rotating saidrollers,

and means for locating a tubeto be filled below said dischargepassageway.

2. Apparatus according to claim 1 in which the innermost points on thelower extremities of said rollers collectively define a circle of adiameter slightly less than the inside diameter of the tube to befilled.

3. Apparatus according to claim 1 in which the axes of said rollers areinclined outwardly. toward their upper ends to enable said amalgam to befunneled downwardly.

4. Apparatus according to claim 3 in which the axes of said rollers areinclined sideways, said rollers being rotated in a direction to impart adownward component of force on the amalgam.

5. Apparatus according to claim 4 in which the outward angle ofinclination is 2 and the sideways angle of inclination is approximately4 6. Apparatus according toclaim 1 further compriss a plurality ofindentations formed on the surface of at least some of said rollers. 7.Apparatus according to claim 1 and a straight tube vertically mountedbelow said discharge passageway.

8. Apparatus according to claim '1 in which said rotating meanscomprises,

a belt passing about said rollers and means for driving said belt torotate said rollers.

9. Apparatus according to claim 1 further comprising, means for rollingsaid amalgam into a ball prior to introducing said amalgam into saidrollers.

10. Apparatus according to claim 1 wherein said support comprises abase,

a column projecting upwardly from said base,

a housing supported on said column,

- a portion of said housing overhanging said base,

said rollers being mounted in said overhanging portion,

a straight tube depending from said housing immediately below saidrollers,

and a dispenser receiver mounted on said base below said tube to receivea dispenser having a curved tube whose end projects into'said straighttube.

11. Apparatus according to claim 10 in which said rotating meanscomprises, 7

a motor in said housing drivably connected to said rollers,

a switch connected to said motor and mounted in said dispenser receiverfor actuation by said dispenser when it is in position to receiveamalgam.

12. Apparatus according to claim 10 in which said dispenser tube iscurved, having an axis forming the arc of a circle. I

13. Apparatus according to claim 12 in which said circle hasapproximately a one inch radius.

14. Apparatus according to claim 7 and a curved dispenser tube havingone end located immediately below said straight tube, said dispensertube having an axis forming the arc of a circle.

15. Apparatus according to claim 14 in which the inner points of thelower extremities of said rollers define a circle of approximately 0.095inch,

said straight tube has an inside diameter of approximately 0.102 inch,and said curved tube has an inside diameter of approximately 0.104 inch.16. Apparatus according to claim 15 in which the inside diameter of theend of said curved tube adjacent said straight tube is approximately0.104 inch, said tube and a wiper mounted to revolve in said trough.tapering down to approximately 0.100 inch. 19. Apparatus according toclaim 1 further compris- 17. Apparatus according to claim 1 furthercomprising, ing, fingers mounted between respective rollers to conahousing surrounding said rollers and having an fine amalgam centrally ofsaid rollers.

opening in the upper end to receive amalgam, 20. Apparatus according toclaim 1 further comprismeans mounted on said housing for rolling amalgaming,

into a ball, three pins mounted on said support, and valve means on saidrolling means for releasing said rollers being mounted on said pins,

a ball of amalgam into said rollers. 10 and said rotating meansincluding an endless belt 18. Apparatus according to claim 17 in whichsaid passing about said rollers to drive said rollers. amalgam rollingmeans comprises a circular trough,

UNITED STATES PATENT OFFICE 7 CERTIFICATE OF CORRECTION Patent 3.785.411Dated Januarv 15, 1974 Inventor(s) Ronald Lee Baker It is certified thaterror appears in the above-identified patent and that said LettersPatent are hereby corrected as shown below:

Column 1, line 34, delete "amalgamators" .and insert variety Column 1,line 35, "amalgamotors" should be amalgamators Column 2, line 22, "into"should be to Signed and sealed this 25th day of June 1974.

(SEAL) Attest:

c. MARSHALL DANN EDWARD M.PLETCHER',JR.

Commissioner of Patents Attesting Officer USCOMM-DC 60376-1 69

1. Apparatus for loading amalgam or the like into a tube comprising, asupport, at least three rollers mounted generally vertically on saidsupport on equiangularly spaced axes, the lower extremities of saidrollers defining among them a discharge passageway, means for rotatingsaid rollers, and means for locating a tube to be filled below saiddischarge passageway.
 2. Apparatus according to claim 1 in which theinnermost points on the lower extremities of said rollers collectivelydefine a circle of a diameter slightly less than the inside diameter ofthe tube to be filled.
 3. Apparatus according to claim 1 in which theaxes of said rollers are inclined outwardly toward their upper ends toenable said amalgam to be funneled downwardly.
 4. Apparatus according toclaim 3 in which the axes of said rollers are inclined sideways, saidrollers being rotated in a direction to impart a downward component offorce on the amalgam.
 5. Apparatus according to claim 4 in which theoutward angle of inclination is 2* and the sideways angle of inclinationis approximately 4*.
 6. Apparatus according to claim 1 furthercomprising, a plurality of indentations formed on the surface of atleast some of said rollers.
 7. Apparatus according to claim 1 and astraight tube vertically mounted below said discharge passageway. 8.Apparatus according to claim 1 in which said rotating means comprises, abelt passing about said rollers and means for driving said belt torotate said rollers.
 9. Apparatus according to claim 1 furthercomprising, means for rolling said amalgam into a ball prior tointroducing said amalgam into said rollers.
 10. Apparatus according toclaim 1 wherein said support comprises a base, a column projectingupwardly from said base, a housing supported on said column, a portionof said housing overhanging said base, said rollers being mounted insaid overhanging portion, a straight tube depending from said housingimmediately below said rollers, and a dispenser receiver mounted on saidbase below said tube to receive a dispenser having a curved tube whoseend projects intO said straight tube.
 11. Apparatus according to claim10 in which said rotating means comprises, a motor in said housingdrivably connected to said rollers, a switch connected to said motor andmounted in said dispenser receiver for actuation by said dispenser whenit is in position to receive amalgam.
 12. Apparatus according to claim10 in which said dispenser tube is curved, having an axis forming thearc of a circle.
 13. Apparatus according to claim 12 in which saidcircle has approximately a one inch radius.
 14. Apparatus according toclaim 7 and a curved dispenser tube having one end located immediatelybelow said straight tube, said dispenser tube having an axis forming thearc of a circle.
 15. Apparatus according to claim 14 in which the innerpoints of the lower extremities of said rollers define a circle ofapproximately 0.095 inch, said straight tube has an inside diameter ofapproximately 0.102 inch, and said curved tube has an inside diameter ofapproximately 0.104 inch.
 16. Apparatus according to claim 15 in whichthe inside diameter of the end of said curved tube adjacent saidstraight tube is approximately 0.104 inch, said tube tapering down toapproximately 0.100 inch.
 17. Apparatus according to claim 1 furthercomprising, a housing surrounding said rollers and having an opening inthe upper end to receive amalgam, means mounted on said housing forrolling amalgam into a ball, and valve means on said rolling means forreleasing a ball of amalgam into said rollers.
 18. Apparatus accordingto claim 17 in which said amalgam rolling means comprises a circulartrough, and a wiper mounted to revolve in said trough.
 19. Apparatusaccording to claim 1 further comprising, fingers mounted betweenrespective rollers to confine amalgam centrally of said rollers. 20.Apparatus according to claim 1 further comprising, three pins mounted onsaid support, said rollers being mounted on said pins, and said rotatingmeans including an endless belt passing about said rollers to drive saidrollers.